1. Field of the Invention
The invention relates to a cutting unit for comminuting bulky feedstock and a device having such a cutting unit.
2. Description of the Background Art
The meaning and purpose of the industrial comminuting of feedstock is often the production of an intermediate product of predefined shape and size, which is then used as the starting material for a subsequent production process. Cited as examples are the comminuting of film bales, which are supplied as shredded film to an agglomerator to produce granules, or the comminuting of large-sized feedstock, such as, for example, rubber bales, which must be reduced to a relatively small final size such as, for example, granules. The uniformity in shape and size of the material leaving a comminuting step in this regard has a significant effect on the quality of the end product produced in the following processing step. In this respect, a precise and reliable precomminuting is extremely important.
DE 10 2004 051 217 A1, which corresponds to U.S. Pat. No. 7,631,825, discloses a device with two-step comminuting, in which rubber bales are converted to granules. The first comminuting step is integrated into the supply channel to the second comminuting step and consists of a cutting unit, whose knife crosses the cross section of the supply channel and thereby divides large-sized bales into smaller pieces. For this purpose, the rubber bale is held by a retaining element, arranged upstream of the knife, in the cutting position, whereas the blade of the knife penetrates through the rubber bale and moves obtusely against a rigid back stop on the opposite wall of the supply channel. Such devices have proven successful in practice in the granulation of large-sized rubber bales.